Handle ForeingTypes in staticdata.c

Author: vchuravy

src/datatype.c

@@ -832,15 +832,13 @@ JL_DLLEXPORT int jl_reinit_foreign_type(jl_datatype_t *dt,
 {
     if (!jl_is_foreign_type(dt))
             return 0;
-    jl_datatype_layout_t *layout = (jl_datatype_layout_t *)
-      jl_gc_perm_alloc(sizeof(jl_datatype_layout_t) + sizeof(jl_fielddescdyn_t),
-        0, 4, 0);
-    *layout = *(dt->layout);
+    const jl_datatype_layout_t *layout = dt->layout;
     jl_fielddescdyn_t * desc =
       (jl_fielddescdyn_t *) ((char *)layout + sizeof(*layout));
+    assert(!desc->markfunc);
+    assert(!desc->sweepfunc);
     desc->markfunc = markfunc;
     desc->sweepfunc = sweepfunc;
-    dt->layout = layout;
     return 1;
 }
 

src/staticdata.c

@@ -77,6 +77,7 @@ External links:
 
 #include "julia.h"
 #include "julia_internal.h"
+#include "julia_gcext.h"
 #include "builtin_proto.h"
 #include "processor.h"
 #include "serialize.h"
@@ -1438,10 +1439,14 @@ static void jl_write_values(jl_serializer_state *s) JL_GC_DISABLED
                 if (dt->layout != NULL) {
                     size_t nf = dt->layout->nfields;
                     size_t np = dt->layout->npointers;
-                    size_t fieldsize = jl_fielddesc_size(dt->layout->fielddesc_type);
+                    size_t fieldsize = 0;
+                    uint8_t is_foreign_type = dt->layout->fielddesc_type == 3;
+                    if (!is_foreign_type) {
+                        fieldsize = jl_fielddesc_size(dt->layout->fielddesc_type);
+                    }
                     char *flddesc = (char*)dt->layout;
                     size_t fldsize = sizeof(jl_datatype_layout_t) + nf * fieldsize;
-                    if (dt->layout->first_ptr != -1)
+                    if (!is_foreign_type && dt->layout->first_ptr != -1)
                         fldsize += np << dt->layout->fielddesc_type;
                     uintptr_t layout = LLT_ALIGN(ios_pos(s->const_data), sizeof(void*));
                     write_padding(s->const_data, layout - ios_pos(s->const_data)); // realign stream
@@ -1450,6 +1455,13 @@ static void jl_write_values(jl_serializer_state *s) JL_GC_DISABLED
                     arraylist_push(&s->relocs_list, (void*)(reloc_offset + offsetof(jl_datatype_t, layout))); // relocation location
                     arraylist_push(&s->relocs_list, (void*)(((uintptr_t)ConstDataRef << RELOC_TAG_OFFSET) + layout)); // relocation target
                     ios_write(s->const_data, flddesc, fldsize);
+                    if (is_foreign_type) {
+                        // make sure we have space for the extra hidden pointers
+                        // zero them since they will need to be re-initialized externally
+                        assert(fldsize == sizeof(jl_datatype_layout_t));
+                        jl_fielddescdyn_t dyn = {0, 0};
+                        ios_write(s->const_data, (char*)&dyn, sizeof(jl_fielddescdyn_t));
+                    }
                 }
             }
             else if (jl_is_typename(v)) {
@@ -2912,6 +2924,7 @@ static void jl_restore_system_image_from_stream_(ios_t *f, jl_image_t *image, jl
             assert(*(void**)dt == (void*)newdt);
             *newdt = *(jl_datatype_t*)dt; // copy the datatype fields (except field 1, which we corrupt above)
             newdt->name = name;
+            assert(newdt->layout->fielddesc_type != 3);
         }
     }
     // we should never see these pointers again, so scramble their memory, so any attempt to look at them crashes

test/gcext/Foreign/deps/foreignlib.c

@@ -3,6 +3,7 @@
 #include "julia.h"
 #include "julia_gcext.h"
 
+// TODO make these atomics
 int nmarks = 0;
 int nsweeps = 0;
 

test/gcext/Makefile

@@ -60,6 +60,8 @@ check: $(BIN)/gcext$(EXE) $(BIN)/LocalTest.jl $(BIN)/Foreign/deps/foreignlib$(DY
 
 clean:
 	-rm -f $(BIN)/gcext-debug$(EXE) $(BIN)/gcext$(EXE)
+	-rm -f $(BIN)/Foreign/deps/foreignlib$(DYLIB)
+	-rm -f $(BIN)/Foreign/deps/foreignlib-debug$(DYLIB)
 
 .PHONY: release debug clean check
 

test/gcext/gcext-test.jl

@@ -45,6 +45,8 @@ end
 @testset "Package with foreign type" begin
     load_path = joinpath(@__DIR__, "Foreign")
     push!(LOAD_PATH, load_path)
+    # Force recaching
+    Base.compilecache(Base.identify_package("Foreign"))
     try
         (@eval (using Foreign))
         @test Base.invokelatest(Foreign.get_nmark)  == 0